Autotransplantation of cryopreserved ovarian tissue in oncological patients: recovery of ovarian function

Prospective solutions to ovarian reserve damage during the ovarian tissue cryopreservation and transplantation procedure

Birth rates continue to decline as more women experience fertility issues. Assisted reproductive technologies are available for patients seeking fertility treatment, including cryopreservation techniques. Cryopreservation can be performed on gametes, embryos, or gonadal tissue and can be used for patients who desire to delay in vitro fertilization treatment. This review focuses on ovarian tissue cryopreservation, the freezing of ovarian cortex containing immature follicles. Ovarian tissue cryopreservation is the only available treatment for the restoration of ovarian function in patients who undergo gonadotoxic treatments, and its wide adoption has led to its recent designation as "no longer experimental" by the American Society for Reproductive Medicine. Ovarian tissue cryopreservation and subsequent transplantation can restore native endocrine function and can support the possibility of pregnancy and live birth for the patient. Importantly, there are multiple steps in the procedure that put the ovarian reserve at risk of damage. The graft is highly susceptible to ischemic reperfusion injury and mass primordial follicle growth activation, resulting in a "burnout" phenomenon. In this review, we summarize current efforts to combat the loss of primordial follicles in grafts through improvements in freeze and thaw protocols, transplantation techniques, and pharmacologic adjuvant treatments. We conducted a review of the literature, with emphasis on emergent research in the last 5 years. Regarding freeze and thaw protocols, we discuss the widely accepted slow freezing approach and newer vitrification protocols. Discussion of improved transplantation techniques includes consideration of the transplantation location of the ovarian tissue and the importance of graft sites in promoting neovascularization. Finally, we discuss pharmacologic treatments being studied to improve tissue performance postgraft. Of note, there is significant research into the efficacy of adjuvants used to reduce ischemic injury, improve neovascularization, and inhibit hyperactivation of primordial follicle growth activations. Although the "experimental" label has been removed from ovarian tissue cryopreservation and subsequent transplantation, there is a significant need for further research to better understand sources of ovarian reserve damage to improve outcomes. Future research directions are provided as we consider how to reach the most hopeful results for women globally.

Fertility in young-onset colorectal patients with cancer: a review

Although the overall incidence and mortality of colorectal cancer have declined, diagnosed cases of young-onset colorectal cancer have increased significantly. Concerns about future fertility are second only to concerns about survival and may significantly affect the quality of life of young cancer survivors. Fertility preservation is an important issue in young-onset colorectal patients with cancer undergoing oncotherapy. Here, we discussed the effects of different treatments on fertility, common options for fertility preservation, factors affecting fertility preservation and improvement measures, and the relationship between fertility and pregnancy outcomes in young-onset colorectal patients with cancer.

Ovarian tissue transplantation: 10 years of experience at the Bologna University

Objective

The efficiency of ovarian tissue transplantation (OTT) was established in terms of ovarian function recovery (95% of cases), number of live births (over 200 worldwide to date) and induction of puberty. Unfortunately, the lack of international registries and the fact that many centers have not yet reported their outcomes, lead to poor knowledge of the exact fertility data. The aim of the study is to describe our experience with OTT to restore ovarian function and fertility.

Methods

This study was designed as a single-center, observational, retrospective, cohort study that includes women who underwent OTT between December 2012 and June 2023 at our center. After approval by the oncologist/hematologist, a small fragment of ovarian tissue was thawed and analyzed to detect the presence of micrometastases before OTT. Thawed ovarian tissue was grafted laparoscopically at multiple sites, including the remaining ovary and pelvic side wall (orthotopic transplantation) and/or abdominal wall (heterotopic transplantation). After OTT, ovarian function was monitored by hormonal assay, ultrasound and color Doppler at approximately 4-week intervals.

Results

Between December 2012 and June 2023, 30 women performed OTT. Prior to OTT, immunohistochemical and molecular analyses revealed no micrometastases in all thawed ovarian tissue samples. In our series of 30 women, 20 of women were on premature ovarian insufficiency (POI), and the remaining ten cases still had oligomenorrhea and difficulty getting pregnant. Among the women with POI before OTT and at least 6 months follow-up, recovery of endocrine function was observed in all but one woman who underwent orthotopic transplantation (13 of 14 cases), in one out of two women who underwent both orthotopic and heterotopic transplantation (1 of 2 cases) and in all women who underwent heterotopic transplantation (4 of 4 cases). Women who underwent OTT to enhance fertility had no alterations in menstrual cycle and hormonal levels. In total, ten pregnancies were obtained in 25 women, resulting in four live births, two ongoing pregnancies and four spontaneous abortions.

Conclusion

Our data can help patients and physicians in their discussions and decisions about the need and possibilities of preserving fertility.

Breast Cancer and Fertility Preservation in Young Female Patients: A Systematic Review of the Literature

INTRODUCTION

Breast cancer affects almost 1.5 million women worldwide below the age of 45 years each year. Many of these women will be advised to undergo adjuvant chemotherapy to minimize the risk of death or recurrence of the tumor. For these patients, chemotherapy is a known cause of infertility, as it can damage primordial follicles, which can lead to early menopause or premature ovarian insufficiency. This systematic review aims to synthesize the current evidence of the most suitable treatments for fertility preservation.

METHODOLOGY

This review was performed following the PRISMA guidelines. The authors conducted an extensive search from the last 15 years. Relevant studies were pursued in PubMed, Embase, and the Cochrane Library up until 31 July 2023. A total of seven eligible studies were identified.

RESULTS

From the reviewed literature, ovarian suppression with gonadotropin-releasing hormone agonists showed promising results in preserving fertility for breast cancer patients undergoing chemotherapy. Additionally, oocyte and embryo cryopreservation demonstrated successful outcomes, with embryo cryopreservation being the most effective option. Notably, the slow-freezing and vitrification methods were both effective in preserving embryos, with vitrification showing superior results in clinical-assisted reproductive technologies. Ovarian tissue cryopreservation emerged as a viable option for prepubertal girls and those unable to undergo conventional ovarian stimulation. The potential of in vitro maturation (IVM) as an alternative method presents a promising avenue for future fertility preservation research.

DISCUSSION

The most suitable treatments for fertility preservation in young patients is the temporary suppression with luteinizing hormone-releasing analogs, while the patient undergoes chemotherapy and cryopreservation. For cryopreservation, the physicians might deem it necessary to either cryopreserve ovarian tissue taken from the patient before any treatment or cryopreserve embryos/oocytes. Cryopreservation of oocytes and/or embryos is the most effective solution for fertility preservation in women of reproductive age, who have a sufficient ovarian reserve and are diagnosed with breast cancer, regardless of the histological type of the tumor. Because approximately 50% of young breast cancer patients are interested in becoming pregnant right after completion of therapy, the evolution and development of fertility preservation techniques promise to be very exciting.

Fertility preservation in pediatric healthcare: a review

Survival rates for children and adolescents diagnosed with malignancy have been steadily increasing due to advances in oncology treatments. These treatments can have a toxic effect on the gonads. Currently, oocyte and sperm cryopreservation are recognized as well-established and successful strategies for fertility preservation for pubertal patients, while the use of gonadotropin-releasing hormone agonists for ovarian protection is controversial. For prepubertal girls, ovarian tissue cryopreservation is the sole option. However, the endocrinological and reproductive outcomes after ovarian tissue transplantation are highly heterogeneous. On the other hand, immature testicular tissue cryopreservation remains the only alternative for prepubertal boys, yet it is still experimental. Although there are several published guidelines for navigating fertility preservation for pediatric and adolescent patients as well as transgender populations, it is still restricted in clinical practice. This review aims to discuss the indications and clinical outcomes of fertility preservation. We also discuss the probably effective and efficient workflow to facilitate fertility preservation.

The use of near-infrared imaging with indocyanine green in the ovarian tissue transplantation: a case report

The request for fertility preservation has consistently increased in recent years. To our knowledge this case report is the first to describe the application of near-infrared intraoperative imaging using indocyanine green (NIR-ICG) during ovarian tissue transplantation (OTT), to assist surgeon choosing the site of implantation of ovarian fragments. OTT was performed in a 42-year-old woman using NIR-ICG to evaluate the vascularisation of peritoneal area as the site of implantation for the ovarian graft. we believe this new approach could be useful in identifying the best reimplantation site.

Ovarian tissue cryopreservation and transplantation: 20 years experience in Bologna University

Objective

To report the 20-year experience in ovarian tissue cryopreservation (OTC) and ovarian tissue transplantation (OTT) of the Bologna clinical center (Bologna, Italy).

Design

Retrospective cohort study.

Patients

1026 pediatrics and women aged between 2 and 38 years who underwent OTC and OTT between January 2002 to January 2022.

Results

Of the 1026 patients, 238 (22.8%) were pediatrics (≤ 17 years, Group 1) and 788 (77.2%) were adult women (range 18-38 years, Group 2). In Group 1, 184 (77.3%) patients had malignant diseases and 54 (22.7%) had non-malignant diseases. In Group 2, 746 (94.7%) patients had malignant diseases and 42 (5.3%) had non-malignant diseases. No real complications were observed during surgery. In all the samples analyzed most of the follicles were in the resting stage, while only a few follicles were growing. In both fresh and thawed samples, follicular density was higher in Group 1 than in Group 2 (p < 0.01). Regardless of age, good preservation of follicles and stroma was observed in fresh and thawed ovarian tissue by histological and immunohistochemical analyses (estrogen and progesterone receptors; Ki67 and Bcl2 markers; TUNEL). To date, out of 1026 total women, 812 (79.1%) had their tissue stored. Sixty-eight (6.6%) patients died from their primary disease. Twenty-four (2.3%) women performed 33 OTTs between December 2011 and January 2022. Restoration of menstruation was observed in 15 out of 17 menopausal women. Six pregnancies were achieved, two hesitated in abortion and four in the birth of healthy babies.

Conclusion

OTC is the only fertility preservation technique applicable in pre-pubertal/pediatrics and in adult patients when stimulation for oocytes/embryos cryopreservation is not possible. The reported data can help future patients and physicians in their discussions and decisions about the need and possibilities of preserving ovarian function.

A comparison of fertility preservation outcomes in patients who froze oocytes, embryos, or ovarian tissue for medically indicated circumstances: a systematic review and meta-analysis

OBJECTIVE

To compare obstetric outcomes in patients cryopreserving reproductive cells or tissues before gonadotoxic therapy.

DESIGN

A literature search was conducted following PRISMA guidelines on Embase, Medline, and Web of Science. Studies reporting obstetric outcomes in cancer patients who completed cryopreservation of oocyte, embryo, or ovarian tissue were included.

SETTING

Not applicable.

PATIENT(S)

Cancer patients attempting pregnancy using cryopreserved cells or tissues frozen before cancer therapy.

INTERVENTION(S)

Oocyte, embryo, or ovarian tissue cryopreservation for fertility preservation in cancer.

MAIN OUTCOME MEASURE(S)

The total numbers of clinical pregnancies, live births, and miscarriages in women attempting pregnancy using cryopreserved reproductive cells or tissues were calculated. A meta-analysis determined the effect size of each intervention.

RESULT(S)

The search returned 4,038 unique entries. Thirty-eight eligible studies were analyzed. The clinical pregnancy rates were 34.9%, 49.0%, and 43.8% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. No significant differences were found among groups. The live birth rates were 25.8%, 35.3%, and 32.3% for oocyte, embryo, and ovarian tissue cryopreservation, respectively, with no significant differences among groups. The miscarriage rates were 9.2%, 16.9%, and 7.5% for oocyte, embryo, and ovarian tissue cryopreservation, respectively. Significantly fewer miscarriages occurred with ovarian tissue cryopreservation than with embryo cryopreservation.

CONCLUSION(S)

This enquiry is required to counsel cancer patients wishing to preserve fertility. Although the limitations of this study include heterogeneity, lack of quality studies, and low utilization rates, it serves as a starting point for comparison of reproductive and obstetric outcomes in patients returning for family-planning after gonadotoxic therapy.

A Systematic Review of Ovarian Tissue Transplantation Outcomes by Ovarian Tissue Processing Size for Cryopreservation

Ovarian tissue cryopreservation (OTC) is the only pre-treatment option currently available to preserve fertility for prepubescent girls and patients who cannot undergo ovarian stimulation. Currently, there is no standardized method of processing ovarian tissue for cryopreservation, despite evidence that fragmentation of ovaries may trigger primordial follicle activation. Because fragmentation may influence ovarian transplant function, the purpose of this systematic review was (1) to identify the processing sizes and dimensions of ovarian tissue within sites around the world, and (2) to examine the reported outcomes of ovarian tissue transplantation including, reported duration of hormone restoration, pregnancy, and live birth. A total of 2,252 abstracts were screened against the inclusion criteria. In this systematic review, 103 studies were included for analysis of tissue processing size and 21 studies were included for analysis of ovarian transplantation outcomes. Only studies where ovarian tissue was cryopreserved (via slow freezing or vitrification) and transplanted orthotopically were included in the review. The size of cryopreserved ovarian tissue was categorized based on dimensions into strips, squares, and fragments. Of the 103 studies, 58 fertility preservation sites were identified that processed ovarian tissue into strips (62%), squares (25.8%), or fragments (31%). Ovarian tissue transplantation was performed in 92 participants that had ovarian tissue cryopreserved into strips (n = 51), squares (n = 37), and fragments (n = 4). All participants had ovarian tissue cryopreserved by slow freezing. The pregnancy rate was 81.3%, 45.5%, 66.7% in the strips, squares, fragment groups, respectively. The live birth rate was 56.3%, 18.2%, 66.7% in the strips, squares, fragment groups, respectively. The mean time from ovarian tissue transplantation to ovarian hormone restoration was 3.88 months, 3.56 months, and 3 months in the strips, squares, and fragments groups, respectively. There was no significant difference between the time of ovarian function' restoration and the size of ovarian tissue. Transplantation of ovarian tissue, regardless of its processing dimensions, restores ovarian hormone activity in the participants that were reported in the literature. More detailed information about the tissue processing size and outcomes post-transplant are required to identify a preferred or more successful processing method.

SYSTEMATIC REVIEW REGISTRATION

[https://www.crd.york.ac.uk], identifier [CRD42020189120].

Ovarian transplantation with robotic surgery and a neovascularizing human extracellular matrix scaffold: a case series in comparison to meta-analytic data

OBJECTIVE

To report our experience with robot-assisted (RA) autologous cryopreserved ovarian tissue transplantation (ACOTT) with the use of a neovascularizing extracellular matrix scaffold.

DESIGN

Case series with meta-analytic update.

SETTING

Academic.

PATIENT(S)

Seven recipients of RA-ACOTT.

INTERVENTION(S)

Before or shortly after initiating chemotherapy, ovarian tissue was cryopreserved from 7 women, who then underwent RA-ACOTT 9.9 ± 1.8 years (range, 7-12 years) later. Perioperatively, they received transdermal estrogen and low-dose aspirin to enhance graft vascularization. Ovarian cortical pieces were thawed and sutured on an extracellular matrix scaffold, which was then robotically anastomosed to the bivalved remaining ovary in 6 cases and retroperitoneally (heterotopic) to the lower abdomen in 1 case.

MAIN OUTCOME MEASURE(S)

Ovarian function return, the number of oocytes/embryos, aneuploidy %, live births, and neonatal outcomes were recorded. Graft longevity was compared with the mean from the meta-analytic data.

RESULT(S)

Ovarian function returned 13.9 ± 2.7 weeks (11-16.2 weeks) after ACOTT, and oocytes were retrieved in all cases with 12.3 ± 6.9 embryos generated. In contrast to orthotopic, the heterotopic ACOTT demonstrated low embryo quality and an 80% aneuploidy rate. A recipient did not attempt to conceive and 2 needed a surrogate, whereas 4 of 4 delivered 6 healthy children, compared with 115 of 460 (25% pregnancy rate) from the meta-analytic data (n = 79). The mean graft longevity (43.2 ± 23.6/47.4 ± 22.8 months with/without sensitivity analysis) trended longer than the meta-analytic mean (29.4 ± 22.7), even after matching age at cryopreservation.

CONCLUSION(S)

In this series, RA-ACOTT resulted in extended graft longevity, with ovarian functions restored in all cases, even when the tissues were cryopreserved after chemotherapy exposure.

Laparoscopic assisted extracorporeal ovarian harvest: A novel technique to optimize ovarian tissue for cryopreservation in young females with cancer

BACKGROUND

Advances in pediatric cancer therapy have improved the long-term survival for many children with cancer. The awareness of quality of life aspects, specifically fertility preservation, has become a reality for many of these families and children. Ovarian tissue cryopreservation has emerged as an available fertility option for young females with cancer. Safe and effective removal of ovarian tissue in these girls is paramount. We report a laparoscopic assisted extracorporeal ovarian harvest technique that achieves this goal.

OPERATIVE TECHNIQUE

We place a 5 mm port at the umbilicus and in the right lower quadrant. Under laparoscopic guidance we place a 12 mm port in the left suprapubic area. Utilizing the 12 mm port site a monofilament traction suture is placed through the left ovary. The traction suture is used to translocate the ovary to an extracorporeal position via the 12 mm port site. Ovarian tissue is then excised utilizing standard surgical technique with the scalpel. Hemostasis is obtained and the capsule is closed with a running absorbable suture. The ovary is placed back in its native position laparoscopically.

CONCLUSIONS

The use of this extracorporeal ovarian harvesting technique is a safe and effective method to optimize removal and minimize tissue injury. Utilization of this technique, may have potential benefit to the young female with cancer.

Ovarian function and reproductive outcome after ovarian tissue transplantation: a systematic review

The aim of this systematic review study is to summarize the current knowledge of ovarian tissue transplantation and provide insight on ovarian function, fertility and reproductive outcome following ovarian tissue transplantation. Relevant studies were identified by searching through PubMed, Cochrane Library, Embase, ProQuest, and Scopus databases until August 2018. Ovarian function by examination of the hormonal level was evaluated, together with follicular growth, the return of menstrual cycle and assessment of reproductive consequences: pregnancy, miscarriage rates and live birth after transplantation. Studies including female patients aged between 22 and 49 years that were subjected to ovarian tissue transplantation were considered. A total of 1185 studies were identified in the primary search. Titles and abstracts were screened for assessment of the inclusion criteria. Finally, twenty-five articles met the criteria and were included in this study. In general, 70% of patients that underwent ovarian tissue transplantation had ovarian and endocrine function restoration as well as follicular growth. Pregnancy was reported with 52% of the patients. The available evidence suggests that ovarian tissue transplantation is a useful and an applied approach to restore hormonal function, endocrine balance and eventually fertility outcomes in patients that are predisposed to lose their fertility, diagnosed with premature ovarian failure (POF), as well as women undergoing cancer treatments. Identification of the techniques with the lowest invasions for follicular and oocyte development after ovarian tissue transplantation aiming to reduce probable adverse effects after treatment is indispensable.

Recent Advances in Fertility Preservation and Counseling for Reproductive-Aged Women with Colorectal Cancer: A Systematic Review

BACKGROUND

The incidence of colorectal cancer among reproductive-aged women is increasing. Concerns regarding future fertility are secondary only to concerns regarding survival and may significantly impact quality of life among reproductive-aged female cancer survivors. Fertility preservation counseling reduces long-term regret and dissatisfaction among cancer survivors. Health care providers counseling patients with colorectal cancer must understand the impact of cancer treatment on future reproductive potential.

OBJECTIVE

This review aims to examine the effects that colorectal cancer treatments have on female fertility and summarize existing and emerging options for fertility preservation.

DATA SOURCES

EMBASE, National Library of Medicine (MEDLINE)/PubMed, Cochrane Review Library were the data sources for this review.

STUDY SELECTION

A systematic literature review was performed using exploded MeSH terms to identify articles examining the effect of surgery, chemotherapy, and radiation, as well as fertility preservation options for colorectal cancer on female fertility. Relevant studies were included.

MAIN OUTCOME MEASURES

The primary outcome was the effect of colorectal cancer treatment on fertility.

RESULTS

There are limited data regarding the impact of colorectal surgery on fertility. The gonadotoxic effects of chemotherapy on reproductive capacity depend on age at the time of chemotherapy administration, cumulative chemotherapy, radiation dose, type of agent, and baseline fertility status. Chemotherapy-induced risks for colorectal cancers are considered low to moderate, whereas pelvic radiation with a dose of 45 to 50 Gray induces premature menopause in greater than 90% of patients. Ovarian transposition may reduce but not eliminate the damaging effect of radiation on the ovaries. Embryo and oocyte cryopreservation are considered standard of care for women desiring fertility preservation, with oocyte cryopreservation no longer being considered experimental. Ovarian tissue cryopreservation remains experimental but may be an option for select patients. The use of gonadotropin-releasing hormone agonists remains controversial and has not been definitively shown to preserve fertility.

LIMITATIONS

The limitations of this review are the lack of randomized controlled trials and high-quality studies, as well as the small sample sizes and the use of surrogate fertility markers.

CONCLUSION

Reproductive-aged women with colorectal cancer benefit from fertility preservation counseling before the initiation of cancer treatment.

Successful achievement after heterotopic transplantations of long-term stored ovarian tissue in Hodgkin's lymphoma survivor

In this case report, we describe the outcomes of two heterotopic transplantations of cryopreserved ovarian tissue performed in a patient with HL, after 11 and 15 years of storage. At the age of 30, the patient underwent laparoscopy to collect ovarian tissue for cryopreservation before chemotherapy and radiotherapy. Eleven years later she experienced premature ovarian failure (POF). As the patient was only interested in endocrine function recovery, two heterotopic ovarian tissue transplantations were performed in the abdominal wall above the rectus muscle respectively 11 and 15 years after cryopreservation. Before transplantation, ovarian samples were analyzed to assess neoplastic contamination and tissue quality. The analysis on thawed ovarian tissue did not reveal micrometastasis and it showed well-preserved follicles and stroma. After both ovarian tissue grafting, menopausal symptoms ceased. The patient had periods approximately every 30-days and hormonal levels were within the premenopausal range. The endocrine function lasted 3-years after the first heterotopic transplantation and is still ongoing after second transplantation. Cryopreservation of ovarian tissue should be proposed to HL patients, as the incidence of POF as a long-term complication is not negligible. In these patients heterotopic transplantation is a useful tool to eliminate menopausal symptoms, preventing osteoporosis and reducing cardiovascular risks.

Transplantation of cryopreserved ovarian tissue in a patient affected by metastatic struma ovarii and endometriosis

In this case report, the outcomes of cryopreserved ovarian tissue transplantation performed in a patient affected by struma-ovarii associated with mature cystic teratoma, recurrent endometriotic cysts and diffuse peritoneal malignant struma-ovarii implants were described. Before cryopreservation, the patient underwent two left ovarian surgeries for enucleation cysts 8 years after righ salpingo-oophorectomy for struma-ovarii. Ovarian biopsy was collected in another hospital and transported to our laboratory for cryopreservation. The patient was submitted to radioiodine-therapy for metastases from malignant struma-ovarii. After treatment she experienced premature ovarian failure. Ten years after cryopreservation, a first orthotopic transplantation was performed in the left ovary and in a peritoneal pocket. Before transplantation, ovarian samples were analyzed to assess neoplastic contamination and tissue quality. Three years later, a second transplantation was heterotopically performed in abdominal subcutaneous sites. The analysis on thawed ovarian tissue did not reveal micrometastasis and they showed follicle and stroma damages. After transplantation few small follicles were observed at ultrasound examination and hormonal levels remained at menopausal values. To date no ovarian function recovery has been observed. The report highlights that ovarian tissue cryopreservation after multiple ovarian surgery may have some limitations. An accurate counseling should be offered to patients who wish to preserve fertility.

Breast cancer and ovarian tissue cryopreservation: Review of the literature

INTRODUCTION

Ovarian tissue cryopreservation is a modern technique of fertility preservation, useful before using ovariotoxic therapies in the treatment of breast cancer. The aim of our literature review was to study ovarian cryopreservation experiences for women with breast cancer, to identify guidelines, constraints and results in the oncological and obstetrical fields.

METHODS

We searched articles through the PubMed/Medline database, including all French and English references from January 2000 to October 2017. The combination of key words "breast cancer" and "ovarian tissue cryopreservation" allowed us to select 50 articles. We kept 18 publications which matched our subject.

RESULTS

Sixteen cases of ovarian transplants among patients treated for breast cancer were published with 14 pregnancies, 11 births and 3 failures. Two cases of breast recurrences were published after ovarian grafting. However, the hindsight in this technique is limited, with a first transplant published in 2004 and only a low number of cases.

PERSPECTIVES

A national census and comprehensive gathering of data among the patients treated for breast cancer using ovarian tissue cryopreservation would make it possible to better evaluate the occurrence of pregnancies and the carcinological risk of this technique.

Transplantation of frozen-thawed ovarian tissue: an update on worldwide activity published in peer-reviewed papers and on the Danish cohort

PURPOSE

The purpose of the study is to review all peer-reviewed published reports of women receiving ovarian tissue transplantation (OTT) with frozen/thawed tissue (OTC) with respect to age, diagnosis, transplantation site, fertility outcome, and potential side effects, including data from all women in the Danish program.

METHODS

A systematic review of the literature was performed in PubMed combined with results from all patients who had received OTT in Denmark up to December 2017.

RESULTS

OTT has been reported from 21 different countries comprising a total of 360 OTT procedures in 318 women. In nine women, malignancy was diagnosed after OTT; none were considered to be directly caused by the OTT. Despite a potential under reporting of cancer recurrence, there is currently no evidence to suggest that OTT causes reseeding of the original cancer. Renewed ovarian endocrine function was reported in 95% of the women. Half of all children born following OTT resulted from natural conception, and newborns were reported to be healthy except for one neonate with a chromosome anomaly with a family disposition. Women who conceived after OTT were significantly younger than those who failed.

CONCLUSION

This study found no indications of sufficient numbers of malignant cells present in the ovarian tissue to cause recurrence of cancer after OTT. Further, it is unlikely that OTC affects the well-being of children born. OTC is now an established method of fertility preservation in Denmark with public reimbursement. The current data encourage that women who require gonadotoxic treatment should be offered an individual evaluation considering fertility preservation.

Current Success and Efficiency of Autologous Ovarian Transplantation: A Meta-Analysis

CONTEXT

Ovarian cryopreservation followed by autotransplantation is still considered an experimental strategy for fertility preservation (FP) mainly because the success rates are unknown.

OBJECTIVE

To determine cohort epidemiologic characteristics and success rates of autologous ovarian tissue transplantation (OTT) with previously cryopreserved tissue.

MATERIALS AND METHODS

Literature review from 1999 to October 1, 2016. Additional cases were retrieved from meeting abstracts and own database. We selected studies that reported autologous OTT with previously banked tissue in humans. We did not include any cases involving fresh ovarian tissue transplantation or those performed to treat idiopathic premature ovarian failure/insufficiency. Both authors reviewed and selected studies for eligibility, which resulted in 59 full-text studies assessed for eligibility. Cases were extracted from original reports and reviews by the junior author, and the senior author reviewed and verified the extracted data.

RESULTS

Nineteen reports were included for qualitative synthesis. In 10 studies, detailed data were available to determine clinical and live birth + ongoing (LB + OG) pregnancy as well as endocrine restoration rates. Three hundred nine OTTs were performed with cryopreserved tissue, resulting in the birth of 84 children and 8 OG pregnancies. The cumulative clinical and LB + OG rates were 57.5% and 37.7%, respectively, and the endocrine restoration rate was 63.9%.

CONCLUSION

Success rates with cryopreserved OTT have reached promising levels. Given these recent data, ovarian tissue cryopreservation should be considered as a viable option for FP.

Long-term storage does not impact the quality of cryopreserved human ovarian tissue

Background

Ovarian tissue cryopreservation is an emerging technique, also addressed to very young cancer patients, for whom it is not possible to perform an ovarian stimulation for oocytes freezing, before gonadotoxic treatment. In this cases, ovarian tissue must be cryopreserved for a long period of time and it is very important to know if it maintains fertility function after a long period of storage. Here we aimed to assess the effect of long-term storage on preservation and viability of cryopreserved human ovarian tissue.

Methods

Descriptive study of three cases of cancer patients whose cryopreserved ovarian tissue remained stored for 18 years. Long-term stored tissue was examined by histological and immunohistochemical analysis, transmission electron microscopy, TUNEL assay and LIVE/DEAD viability/citotoxicity test.

Results

Ovarian tissue stored for 18 years showed a good morphology. Follicles presented negative staining for estrogen and progesterone receptors, positive staining for ki67 in granulosa cells and/or oocytes and for bcl2 in granulosa cells. Regarding stroma, patch/focal positive expression was found for estrogen receptor and ki67, diffusely positive expression for progesterone receptor and bcl2. After long-term storage, ultrastructural examination showed sub-cellular integrity of follicles and interstitial oedema foci. No apoptosis was observable by TUNEL assay. Stromal cell viability remained >97 % during the culture period.

Conclusion

The evaluation of different aspects of the tissue provides evidence that the storage time does not impact on tissue quality and gives hope especially to cancer girls, whose tissues could remain cryopreserved for a very long time.

Morphological, ultrastructural and functional imaging of frozen/thawed and vitrified/warmed human ovarian tissue retrieved from oncological patients

STUDY QUESTION

Which is the best method for human ovarian tissue cryopreservation: slow freezing/rapid thawing (SF/RT) or vitrification/warming (V/W)?

SUMMARY ANSWER

The conventional SF/RT protocol used in this study seems to better preserve the morpho-functional status of human cryopreserved ovarian tissue than the used open carrier V/W protocol.

WHAT IS KNOWN ALREADY

Cryopreservation of human ovarian tissue is generally performed using the SF/RT method. However, reduction in the follicular pool and stroma damage are often observed. An emerging alternative procedure is represented by V/W which seems to allow the maintenance of the morphological integrity of the stroma.

STUDY DESIGN, SIZE, DURATION

This is a retrospective cohort study including six patients affected by oncological diseases and enrolled from January to December 2014.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Ovarian tissue was laparoscopically harvested from the right and left ovaries and was cryopreserved using a routinary SF/RT protocol or a V/W method, involving tissue incubation in two solutions (containing propylene glycol, ethylene glycol and sucrose at different concentrations) and vitrification in an open system. For each patient, three pieces from each ovary were collected at the time of laparoscopy (fresh tissue) and after storage (SF/RT or V/W) and processed for light microscopy (LM) and transmission electron microscopy (TEM), to assess the morphological and ultrastructural features of follicles and stroma, and for laser scanning confocal microscopy (LSCM), to determine the functional energetic/redox stroma status. The preservation status of SF/RT and V/W ovarian tissues was compared with that of fresh ones, as well as between them.

MAIN RESULTS AND THE ROLE OF CHANCE

By LM and TEM, SF/RT and V/W samples showed cryodamage of small entity. Interstitial oedema and increased stromal cell vacuolization and chromatin clumping were observed in SF/RT samples; in contrast, V/W samples showed oocyte nuclei with slightly thickened chromatin and irregular shapes. The functional imaging analysis by LSCM revealed that the mitochondrial activity and intracellular reactive oxygen species levels were reduced both in SF/RT and in V/W samples compared with fresh samples. The study also showed progressive dysfunction of the mitochondrial activity going from the outer to the inner serial section of the ovarian cortex. The reduction of mitochondrial activity of V/W samples compared with fresh samples was significantly higher in the inner section than in the outer section.

LIMITATIONS, REASONS FOR CAUTION

The results report the bioenergetic and oxidative status assessment of fresh and cryopreserved human ovarian tissue by LSCM, a technique recently applied to tissue samples. The use of LSCM on human ovarian tissues after SF/RT or V/W is a new application that requires validation. The procedures for mitochondrial staining with functional probes and fixing are not yet standardized. Xenografting of the cryopreserved ovarian tissue in severe combined immunodeficient mice and in vitro culture have not yet been performed.

WIDER IMPLICATIONS OF THE FINDINGS

The identification of a cryopreservation method able to maintain the morpho-functional integrity of the ovarian tissue and a number of follicles comparable with those observed in fresh tissue might optimize results in clinical practice, in terms of recovery, duration of ovarian function and increased delivery outcomes after replanting. The SF/RT protocol allowed better morpho-functional tissue integrity than the V/W procedure.

STUDY FUNDING/COMPETING INTERESTS

Funding was provided by Fondazione del Monte di Bologna e Ravenna, Italy. Dr N.A.M. was granted by the project ONEV MIUR PONa3 00134-n.254/R&C 18 5 2011 and the project GR-2011-02351396 (Ministry of Health, Young Researchers Grant 2011/2012). There are no competing interests.

TRIAL REGISTRATION NUMBER

Clinical trial 74/2001/0 (approved:13 2 2002): 'Pilot study on cryopreservation of human ovarian tissue: morphological and immunohistochemical analysis before and after cryopreservation'.